A coding artifacts removal algorithm based on spatial and temporal regularization

In this paper, we propose a new video post-processing algorithm for reducing coding artifacts. The algorithm is based on regularized image restoration technique, in which a nonconvex regularization function is used to enforce smoothness constraints on the spatial image pixels for suppressing coding artifacts while preserving important image attribute. Temporal regularization is carried out along the motion trajectories. We apply half-quadratic regularization and piecewise constraint strategy to simplify the optimization problem. Explicit filtering formulae are obtained and a recursive filtering algorithm is developed. Experimental results demonstrate that the proposed method can significantly improve both subjective and objective quality of MPEG-4 coded video sequences in comparison with the postprocessing technique in MPEG-4.